Update .npmignore to prevent packaging tmp dir
Update .npmignore to prevent packaging tmp dir

The ember-cli addon blueprint generates the .npmignore and previous to 0.2.2 did not ignore the tmp directory causing large packages. This change is direct from https://github.com/ember-cli/ember-cli/pull/3539

ilovezy/ember-table,Flexberry/ember-table,shaunc/ember-table,Gaurav0/ember-table,winweb/ember-table,fuse-mars/ember-table,artych/ember-table,remerge/ember-table,ajgordo/ember-table,kaikoehn/ember-table,ajgordo/ember-table,Gaurav0/ember-table,remerge/ember-table,hedgeserv/ember-table,morten-holm/ember-table,artych/ember-table,fuse-mars/ember-table,kaikoehn/ember-table,ilovezy/ember-table,morten-holm/ember-table,hedgeserv/ember-table,Flexberry/ember-table,shaunc/ember-table,winweb/ember-table